"I'm 54. Have been in sw dev for 40 years.....Last year I applied for 300 positions,..."
Being somewhat older than you, but bored, I think about taking up the oar again. My problem doubles down on yours in that my background is all in products with an expensive hardware component or workstation software, neither appears to be a growth industry.
Aside from the inevitable well-meaning advice to become some sort of 'project manager', etc. I wonder if it makes any sense to hit the .gov job markets at all.
Has anyone done that at an advanced age?